The present invention is directed to an equipment for working a hard material and includes a housing, a driving motor located within the housing, a tool connected to the driving motor and arranged to work the hard material, a cooling duct located within the housing in a region about the driving motor. A coolant supply source supplies coolant under pressure via a coolant supply pipeline to the coolant duct. After flow through the coolant duct, coolant passes into a coolant discharge pipeline.
To produce boreholes or openings in hard materials, drilling or cutting equipment is used including tools tipped with cutting segments formed of diamond particles. Such equipment must perform differently, depending on the hardness of the material or the depth of the borehole or cuts to be produced. Particularly in high-powered equipment, heat is developed in the drilling or cutting process in the region of the driving motor and in the region of the associated electronic components and can lead to interference with the control of the equipment. In the region of components for controlling the equipment, including at least one electronic component, high temperatures can be produced by heat accumulation, by surrounding high temperatures or by inadequate ventilation of the electronic component if it happens to be covered with dust, or its ventilation slots are closed off almost completely by dust accumulation, so that surrounding cooling air can no longer reach the electronic component.
To dissipate the heat developing in the region of a driving motor while working a hard material, drilling equipment with a drilling motor is disclosed in DE 43 30 520 in connection with a drilling tool, a part of the housing, surrounding the driving motor, being traversed by a cooling duct running spirally from an inlet, located opposite the drilling direction, over the entire driving motor to an outlet on the drilling side. A coolant is passed through the cooling duct under pressure from an external coolant supply source and is supplied to the inlet by a coolant supply pipeline. A coolant discharge pipeline extends from the outlet from the cooling duct to the drilling tool. Aside from cooling the drilling tool, the coolant supplied through the coolant discharge pipeline to the drilling tool also serves to flush drillings out of the drilled borehole and in certain applications, coolant must be prevented from reaching the drilling tool. In such a case, the coolant discharge pipeline connects the cooling duct outlet with the coolant supply source.
In the drilling equipment disclosed in the DE 43 30 520, only the driving motor is cooled with coolant. In the region of the electronic components, however, which controls the driving motor, heat can increase greatly and lead to interference with the control of the drilling equipment.